The present disclosure relates to antibodies, and particularly to antibodies that bind to the OX40 receptor.
Enhancing anti-tumor T cell function represents a powerful and novel approach for cancer treatment. Crucial components involved with generating an effective anti-tumor T cell response include enhancing CD4+ helper T cell activity to promote the generation of anti-tumor cytolytic T cells, and providing survival signals for memory and effector T cells. A key receptor that has been shown to mediate these responses is the OX40 receptor. Sugamura, K., Ishii, N., Weinberg, A. Therapeutic targeting of the effector T-cell co-stimulatory molecule OX40. Nature Rev. Imm. 4: 420-431 (2004); Hori, T. Roles of OX40 in the pathogenesis and control of diseases. Intn. J. Hematology. 83: 17-22 (2006).
The OX40 receptor (OX40R) (also known as CD134, TNFRSF4, ACT-4, ACT35, and TXGP1L) is a member of the TNF receptor superfamily. The OX40R is found to be expressed on activated CD4+ T-cells. High numbers of OX40R+ T cells have been demonstrated within tumors (tumor infiltrating lymphocytes) and in the draining lymph nodes of cancer patients (Vetto, J. T. et al. 1997. Presence of the T-cell. activation marker OX-40 on tumor infiltrating lymphocytes and draining lymph nodes cells from patients with melanoma and head and neck cancers. Am. J. Surg. 174: 258-265; Weinberg, A. D. et al. Engagement of the OX-40 receptor in vivo enhances antitumor immunity. J. Immunol. 164: 2160-69 (2000); Petty, J. K., et al. Survival in human colorectal cancer correlates with expression of the T-cell costimulatory molecule OX-40 (CD134). Am. J. Surg. 183: 512-518 (2002)). It was shown in tumor models in mice that engagement of the OX40R in vivo during tumor priming significantly delayed and prevented the appearance of tumors as compared to control treated mice (Weinberg et al., 2.000). Therefore, it has been contemplated to enhance the immune response of a mammal to an antigen by engaging the OX40R through the use of an OX40R binding agent (WO 99/42585: Weinberg et al, 2000).